It is known that from time to time farmers are required to treat animals with fluid medicament. The medicament can be applied to the animal in the form of a vaccine, oral drench or pour on supplied from a bottle, pack or container capable of treating multiple animals. In all cases an applicator is used to apply the medicament to the animal.
A problem with such applicators is hand strain and fatigue for the farmer. This is noticeable when treating large numbers of animals and when applying larger doses of medicament.
Another problem with such applicators is most medicaments are dosed on weight. When dosing a group of animals, the farmer will set the applicator to suit the heavier animals and dose all the animals with the same amount. This results in over dosing of many animals and wasting of medicament.
Another problem with such applicators is a second spurt caused when the fluid in the supply tube is stopped quickly and the valves in the dispenser are unable to shut off the fluid immediately resulting in a second small dose being delivered. Increasing the spring force in the valves fixes the problem however this makes the applicator too difficult to operate.
Another problem with such applicators is there is no electronic means to record the animal identity, medicament, dose size and date.
Powered applicators have been developed to overcome the problem of hand strain and fatigue however these applicators are bulky, have the pumps mounted away from the operator and either run on mains power or are powered by pneumatic air supply. Some examples of art applicators include the following provided by way of example only.
NZ247457 describes a gun dispenser with a motor and batteries in the hand piece. The gun described does not have a separate chamber inlet and outlet. The dispenser is designed to expel fluid and no motorised and automated refilling is described. In addition, the motor is offset below the outlet axis making the dispenser bulky, unbalanced and difficult to control/aim.
NZ509851 describes a drench gun that relies on varying the motor speed in order to alter the volume of fluid dispensed from the gun. There is no separate chamber on the hand piece and the device is very reliant on the controller and motor accuracy to ensure the correct volume of fluid is dispensed.
NZ523949 describes a non-powered drench gun which has a fluid chamber in front of the piston and a chamber behind the piston. The piston has a non-return valve such that forward movement of the piston expels fluid from the front chamber and at the same time draws fluid from the reservoir into the rear chamber. The return stroke of the piston transfers fluid from the rear chamber to the front chamber, the chambers both containing the working fluid requiring a plunger that divides the chambers and integrated non-return valve between the chambers.
US2002/0107501 describes a weight dependent, automatic filling dosage system. The system has a separate pump that fills the syringe with the desired dosage. The operator has to squeeze the syringe handle to administer the dose, so the operator is still doing most of the work leading to the potential of injury. In addition, having separate components means the system is more cumbersome and less mobile.
It should be appreciated that it may be useful to address one or more of the above disadvantages or at least provide the public with a useful choice.
Further aspects and advantages of the dispenser will become apparent from the ensuing description that is given by way of example only.